80 APPENDIX TO THE EEPORT OF THE SECRETARY. 



fully remeasiired, with a probable error of 1.5 inclies, as well as tlie 

 southern portion of the chain of triangles connecting it with the Gun- 

 nison base-line. The main change of triangnlation, consisting of eight 

 quadrilaterals, one triangle, and one pentagon, is now ready for discus- 

 sion. At each end of the chain a base-line has been measured, and an 

 astronomical determination has been made of latitude, longitude, and 

 azimuth. The most southerly points visited were Mount San Francisco 

 and Mount Floyd, volcanic peaks on the (Colorado plateau south of 

 Grand Canon. Southern Utah is not w^ell adapted for triangnlation. 

 Its principal eminences are table-lands or plateaus covered with timber, 

 there being very few sharj) peaks readily distinguishable from all direc- 

 tions. 



The work of Mr. Eenshaw's party, with plane-table and orograph, em- 

 braces all of the region lying south of the Grand Caiion in sections 105 

 and 100, covering about 7,500 square miles. This field comijrised a 

 portion of what is known as the Colorado Plateau, a high table-land 

 lying immediately south of the Colorado Eiver, which there runs west- 

 wardly at the bottom of a deep chasm. On the southern edge of the 

 plateau there are innumerable extinct volcanoes, the ground being 

 covered by a forest of pine, the most valuable tract of timber in Arizona. 

 The northern edge is lower, and is bare of timber. Kear the Colorado 

 Caiaon it is broken by gorges, and is difficult of access, but in other 

 directions there is little impediment to travel. Water is scarce, and is 

 found only in pockets and small springs, there being none available for 

 irrigation. The only wealth of the country lies in timber and grass. 

 West of the plateau, Mr. Eenshaw's map includes a portion of Hualapai 

 Valley and the adjacent mountains. This region is almost an absolute 

 desert, water being so scarce that in some places it is sold by the gallon. 

 Agriculture is out of the question, and there is no timber. Grazing is 

 practicable to a limited extent. The only important industry, present or 

 prospective, is mining, and only the richest of the numerous gold and 

 silver deposits can now be worked with profit, owing to the remoteness 

 of all sources of supplies. 



Mr. Wheeler worked with iilane-table and orograph in the western 

 half of the region comprised by atlas-sheet oSTo. lOG, and estimates his 

 total area at 5,000 square miles. Through the centre of his district there 

 runs from nortli to south a natural barrier called the Echo Cliff. The 

 escarpment faces westward, and the plateau at the west of it is 1,000 

 feet lower than that to the eastward. The eastern plateau is a broad 

 desert of sand, scantily watered, and useful only for grazing purj^oses. 

 The western plateau is equally barren and worthless, but presents more 

 variety of surfiice. A portion consists of naked "bad lands," soft strata 

 carved by the elements into hills of picturesque beauty, and tinted with 

 a variety of brilliant colors which warrant the title of Painted Desert, 

 bestowed by Lieutenant Ives. Another portion is extremely rocky, and 

 divided by a net-work of impassable caiions. Through this region runs 



